I use Reloader 15 with a foam filler rod and 500 grains bullets. Accurate and same velocities as H 4831. Felt recoil is much less than the 106 grains of H 4831. Somewhere around 86 or 87 grains of Reloader 15 is about right. Do a search on the Accurate Reloading.com forum and a lot of information will turn up. Mine is a Chapuis SXS double and it has plenty of power and a fun gun to play with. Perfect choice for the rabbits in the garden patch!